Refrigerator

ABSTRACT

An ice-maker in a refrigerator is capable of producing ice pieces through directly cooling by a refrigerant circulating in a cold air generation system. An ice-making pipe is installed within the ice-making unit and has the refrigerant flowing therein. A refrigerant pipe is installed in the refrigerator main body for receiving the refrigerant from the cold air generation system. A flexible pipe is disposed around hinged end portions (e.g., corners) of the refrigerator main body and the door and configured to interconnect the ice-making pipe and the refrigerant pipe in an extendable manner. A control valve can cut off a flow of the refrigerant flowing between the ice-making pipe and the refrigerant pipe, for example when the door is to be removed for repair or replacement.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority from Korean PatentApplication No. 10-2016-0044318, filed on Apr. 11, 2016, the disclosureof which is incorporated herein in its entirety by reference for allpurposes.

TECHNICAL FIELD

Embodiments of the present disclosure relate to refrigerators, and moreparticularly, to ice making and dispensing mechanisms in refrigerators.

BACKGROUND

A refrigerator is an appliance used for storing food or other times atlow temperature, e.g., in a frozen state or refrigerated.

The interior of the refrigerator is cooled by cold air circulatingtherein. Cold air can be continuously generated as a refrigerantrecycling through compression, condensation, expansion and evaporation.Cold air supplied in the refrigerator is uniformly distributed byconvection.

The refrigerator includes a main body having a rectangularparallelepiped shape with a front opening. A refrigeration compartmentand a freezer compartment may be disposed in the main body. Arefrigeration compartment door and a freezer compartment door may coverthe front of the main body. Drawers, racks, storage boxes and the likefor sorting different kinds of items may be disposed in the internalstorage space of the refrigerator.

In general, a top-mount-type refrigerator has a freezer compartmentlocated on top of a refrigeration compartment. In contrast, abottom-freezer-type refrigerator has a freezer compartment located underthe refrigeration compartment. This enables a user to convenientlyaccess the refrigeration compartment. On the other hand, this may beinconvenient for a user to access the freezer compartment, if the userhas to bend or lower his or her body to reach, e.g., to take out icepieces.

Some bottom-freezer-type refrigerators have an ice dispenser disposed ina refrigeration compartment door located at the upper side of therefrigerator. In this case, an ice-making device for supplying ice maybe disposed in the refrigeration compartment door or the interior of therefrigeration compartment.

If an ice-making device is installed in a refrigeration compartmentdoor, air cooled by an evaporator becomes cold air and is supplied toboth the freezer compartment and the refrigeration compartment. Cold airentering the freezer compartment flows toward the ice-making devicealong a cold air supply duct embedded in a sidewall of the refrigeratormain body. Water freezes into ice pieces as cold air flows through theinterior of the ice-making device. Thereafter, cold air in theice-making device is discharged to the refrigeration compartment via acold air return duct embedded in the sidewall of the refrigerator mainbody.

However, in a conventional refrigerator, the cold air supply duct, thecold air return duct and a structure for insulating the ducts need to beinstalled on the left or right wall of the refrigeration compartment,which undesirably reduces usable storage space therein. In addition,this configuration makes the overall internal pipe arrangementundesirably complex.

Furthermore, since ice pieces are produced by indirect cooling whichrelies on cold air flowing through the cold air supply duct, the coolingefficiency and so the ice producing efficiency are fairly low andusually unsatisfactory.

Patent Document: Korean Patent No. 10-0565621 (registered on Mar. 22,2006)

SUMMARY

Embodiments of the present disclosure provide a refrigerator capable ofmaking ice pieces within an ice-making compartment of a door by a directcooling method using a refrigerant.

In accordance with an embodiment of the present disclosure, arefrigerator includes: a refrigerator main body; a door coupled to therefrigerator main body; an ice-making unit installed in the door; a coldair generation system configured to circulate a refrigerant to generatecold air supplied to the interior of the refrigerator; an ice-makingpipe installed within the ice-making unit so that the ice-making unitexchanges heat with the refrigerant; a refrigerant pipe installed in therefrigerator main body to receive the refrigerant from the cold airgeneration system; a flexible pipe configured to interconnect theice-making pipe and the refrigerant pipe in an extendable manner; and acontrol valve configured to selectively cut off a flow of therefrigerant flowing between the ice-making pipe and the refrigerantpipe.

The flexible pipe may be disposed in hinged end portions of therefrigerator main body and the door.

The flexible pipe may be disposed around a hinge shaft of therefrigerator main body and the door.

The control valve may include an opening/closing valve installed in atleast one of an end portion of the refrigerant pipe or an end portion ofthe ice-making pipe.

The cold air generation system may include an evaporator enabling heattransfer between the refrigerant and air so that cold air is generatedand supplied to the internal space of the refrigerator main body; acompressor configured to phase-change the refrigerant supplied from theevaporator to gaseous phase refrigerant having high temperature and highpressure; a condenser configured to phase-change the gaseous refrigerantto liquid refrigerant having high pressure; and an expansion valveconfigured to depressurize the liquid refrigerant and to supply theliquid refrigerant to the evaporator.

The ice-making unit may include an ice-making compartment configured toprovide an ice-making space; an ice-making tray contacting theice-making pipe so that ice pieces are produced through heat exchangewith the refrigerant; and an ice bucket positioned under the ice-makingtray to store ice pieces.

In accordance with a second embodiment of the present invention, thereis provided a refrigerator, including: a refrigerator main body; a door;an ice-making unit mounted in the door; a cold air generation systemconfigured to circulate a refrigerant; and a direct cooling unitconfigured to selectively supply the refrigerant from the cold airgeneration system to the ice-making unit through a control valve. Theice-making unit includes: an ice-making compartment configured toprovide an ice-making space; an ice-making tray configured to provide aframe which contacts the ice-making pipe so that ice pieces are producedthrough heat exchange with the refrigerant; and an ice bucket positionedunder the ice-making tray to store the ice pieces.

The direct cooling unit may include an ice-making pipe installed withinthe ice-making unit with the refrigerant flowing therein; a refrigerantpipe installed in the refrigerator main body to supply the refrigerantfrom the cold air generation system to the ice-making pipe; a controlvalve configured to selectively cut off a flow of the refrigerantflowing between the ice-making pipe and the refrigerant pipe; and aflexible pipe configured to interconnect the ice-making pipe and therefrigerant pipe in a stretchable or twistable manner.

According to the embodiments of the present disclosure, refrigerant inthe refrigerator-main-body-side refrigerant pipe is supplied to therefrigerator-door-side ice-making pipe. Thus, ice pieces can be producedthrough direct cooling by the refrigerant, without relying on a supplyof cold air to the ice-maker and thereby ice production is accomplishedwith high cooling efficiency. Also, the ice-making speed can besignificantly improved.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be better understood from areading of the following detailed description, taken in conjunction withthe accompanying figures, in which like reference characters designatelike elements and in which:

FIG. 1 is a perspective view illustrating an exemplary refrigeratoraccording to a first embodiment of the present disclosure;

FIG. 2 is a view illustrating an exemplary arrangement of an ice-makingpipe, a refrigerant pipe and a flexible pipe in the refrigeratoraccording to the first embodiment of the present disclosure;

FIG. 3 is a view illustrating an exemplary arrangement of an ice-makingpipe, a refrigerant pipe and a flexible pipe in the refrigeratoraccording to a modification of the first embodiment of the presentdisclosure;

FIG. 4 is a side sectional view illustrating the internal configurationof an exemplary ice-making unit of the refrigerator illustrated in FIG.1;

FIG. 5 is a plan view illustrating the internal configuration of anexemplary ice-making unit of the refrigerator illustrated in FIG. 1;

FIG. 6 is a block diagram illustrating an exemplary cold air generationsystem of the refrigerator according to the first embodiment of thepresent disclosure;

FIG. 7 is a block diagram illustrating a cold air generation system ofthe refrigerator according to a modification of the first embodiment ofthe present disclosure;

FIG. 8 is a perspective view illustrating an exemplary refrigeratoraccording to a second embodiment of the present disclosure; and

FIG. 9 is a view illustrating an exemplary arrangement of an ice-makingpipe, a refrigerant pipe and a flexible pipe in the refrigeratoraccording to the second embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, configurations and operations of embodiments will bedescribed in detail with reference to the accompanying drawings. Thefollowing description is one of various patentable aspects of thedisclosure and may form a part of the detailed description of thedisclosure.

However, in describing the disclosure, detailed descriptions of knownconfigurations or functions that make the disclosure obscure may beomitted.

The disclosure may be variously modified and may include variousembodiments. Specific embodiments will be exemplarily illustrated in thedrawings and described in the detailed description of the embodiments.However, it should be understood that they are not intended to limit thedisclosure to specific embodiments but rather to cover allmodifications, similarities, and alternatives which are included in thespirit and scope of the disclosure.

The terms used herein, including ordinal numbers such as “first” and“second” may be used to describe, and not to limit, various components.The terms simply distinguish the components from one another. When it issaid that a component is “connected” “coupled” or “linked” to anothercomponent, it should be understood that the former component may bedirectly connected or linked to the latter component or a thirdcomponent may be interposed between the two components. Specific termsused in the present application are used simply to describe specificembodiments without limiting the disclosure. An expression used in thesingular encompasses the expression of the plural, unless it has aclearly different meaning in the context.

Hereinafter, one embodiment of the present disclosure will be describedwith reference to the accompanying drawings.

FIG. 1 is a perspective view illustrating an exemplary refrigeratoraccording to a first embodiment of the present disclosure. FIG. 2 is aview illustrating an exemplary arrangement of an ice-making pipe, arefrigerant pipe and a flexible pipe in the refrigerator according tothe first embodiment of the present disclosure. FIG. 3 is a viewillustrating an exemplary arrangement of an ice-making pipe, arefrigerant pipe and a flexible pipe in the refrigerator according to amodification of the first embodiment of the present disclosure. FIG. 4is a side sectional view illustrating the internal configuration of anexemplary ice-making unit of the refrigerator illustrated in FIG. 1.FIG. 5 is a plan view illustrating the internal configuration of anexemplary ice-making unit of the refrigerator illustrated in FIG. 1.

As illustrated in FIGS. 1 to 5, the refrigerator according to a firstembodiment of the present disclosure may include a refrigerator mainbody 10 configured to define an outer body of the refrigerator, a door20 configured to open and close an internal space of the refrigeratormain body 10, an ice-making unit 30 provided in the door 20, a cold airgeneration system 40 configured to circulate a refrigerant, and a directcooling unit 100 configured to supply the refrigerant of the cold airgeneration system 40 to the ice-making unit 30 via a stretchableflexible pipe 130 and configured to control a flow of the refrigerantwith a control valve.

More specifically, the refrigerator main body 10 is a housing configuredto define an outer body of the refrigerator and may be partitioned intoa freezer compartment F and a refrigeration compartment R by a barrier12. For example, the freezer compartment F may be located in a lowerportion of the refrigerator main body 10 and the refrigerationcompartment R may be located in an upper portion of the refrigeratormain body 10. The freezer compartment F and the refrigerationcompartment R are covered by the door 20.

The door 20 may include a refrigeration compartment door configured toseal the refrigeration compartment R at the opposite edges of the frontsurface of the refrigerator main body 10 and a freezer compartment doorconfigured to seal the front opening of the freezer compartment F.

In the present embodiment, the refrigeration compartment door having theice-making unit 30 is configured to cover the refrigeration compartmentR. The ice-making unit 30 may also be disposed in the freezercompartment door on the freezer compartment F. In addition, therefrigerator according to the present embodiment is abottom-freezer-type refrigerator in which the freezer compartment F ispositioned at the lower side. However, the present disclosure is notlimited thereto. The present disclosure may be applied to differenttypes of refrigerators.

The ice-making unit 30 may include: an ice-making compartment 32providing an ice-making space for producing ice pieces; an ice-makingtray 33 configured to exchange heat with the refrigerant to produce icepieces; an ice bucket 34 positioned under the ice-making tray 33; arotary motor 36 configured to rotate the ice-making tray 33 to releasethe ice pieces from the ice-making tray 33 into the ice bucket 34; and aheater 35 disposed in a peripheral edge portion of the ice-making tray33.

The ice-making tray 33 receives water from a water supply pipe (notshown). A plurality of cells capable of accommodating water may beformed in the ice-making tray 33. The cells may have different shapes ornumbers in different embodiments.

The ice-making tray 33 may be made of metal having high thermalconductivity. The lower surface of the ice-making tray 33 may directlycontact an ice-making pipe 110. The ice-making pipe 110 contacting theice-making tray 33 may have a U-shaped contact portion 110 a. Forexample, the contact portion 110 a of the ice-making pipe 110 may extendfrom one end of the ice-making tray 33 and may be bent 180 degrees inthe vicinity of the other end of the ice-making tray 33. Then, thecontact portion 110 a may extend toward the one end of the ice-makingtray 33.

The present disclosure is not limited to this specific implementation.The contact portion 110 a of the ice-making pipe 110 may be bentmultiple turns and may be formed to serpentine (e.g., routed back andforth) at multiple times on the lower surface of the ice-making tray 33.To enhance heat transfer efficiency, the ice-making tray 33 and theice-making pipe 110 may be bonded together using an adhesive agent orfastener.

Thus, refrigerant supplied from the refrigerant pipe 120 to theice-making pipe 110 can directly exchange heat with water contained inthe ice-making tray 33 without requiring a cold air supply to the tray.Particularly, the heat exchange occurs through the contact portion 110 aof the ice-making pipe 110. As a result, the water freezes andtransforms to ice pieces. In this manner, the operation and effect ofthe contact portion 110 a of the ice-making pipe 110 resemble asmall-scale evaporator in the cold air generation system.

As described above, in the present embodiment, ice pieces may beproduced by direct cooling through heat exchange between the ice-makingpipe 110 and the ice-making tray 33, without relying on any supply ofcold air to the tray. In contrast, in a conventional system, cold airsupplied from a refrigerator main body is supplied to and cools anice-making tray through gas-to-solid heat exchange. In this manner,refrigerant cannot cool the tray directly but through the intermediatemedium, e.g., cold air. Thus, according to embodiments of the presentdisclosure, time required for producing a batch of ice pieces can besignificantly shortened.

Ice pieces thus produced may be transferred by the rotary motor 36 ontothe ice bucket 34 that is disposed under the ice-making tray 33. At thispoint, the heater 35 may heat the ice-making tray 33 for a short periodof time, thereby slightly melting the surfaces of the ice piecescontacting the ice-making tray 33 so that the ice pieces are easilyseparated from the ice-making tray 33.

If the upper surface of the ice-making tray 33 is rotated toward the icebucket 34, the ice-making tray 33 can be twisted, e.g., at apredetermined angle or more, to release the ice pieces to the ice bucket34. Ice pieces in the ice bucket 34 are then placed between blades of anauger 37. When the auger 37 is rotated, the ice pieces may be suppliedto a user through a dispenser (not shown) on the door 20.

The direct cooling unit 100 may include an ice-making pipe 110 installedin the ice-making unit 30, a refrigerant pipe 120 installed in therefrigerator main body 10, a flexible pipe 130 configured tointerconnect the ice-making pipe 110 and the refrigerant pipe 120, acontrol valve configured to control a flow path of the refrigerantflowing between the ice-making pipe 110 and the refrigerant pipe 120,and a pipe case 140 configured to surround an end portion of therefrigerant pipe 120.

The ice-making pipe 110 may be installed in the ice-making compartment32 so that at least a portion (e.g., the contact portion 110 a) of theice-making pipe 110 directly contacts the ice-making tray 33 of theice-making unit 30. Thus, refrigerant supplied to the ice-making pipe110 may rapidly cool the water in the ice tray through direct heatexchange with the ice-making tray 33, especially through the contactportion 110 a of the ice-making pipe 110.

The refrigerant pipe 120 is a pipe branched from a refrigerant line 45of the cold air generation system 40. The refrigerant pipe 120 may bebranched from the cold air generation system 40 so that the end portionof the refrigerant pipe 120 is horizontally positioned in a side wall ofthe refrigerator main body 10. The refrigerant pipe 120 may include aninflow refrigerant pipe configured to supply refrigerant from the coldair generation system 40 to the ice-making pipe 110 and an outflowrefrigerant pipe configured to return refrigerant from the ice-makingpipe 110 to the cold air generation system 40.

The refrigerant pipe 120 is coupled to the ice-making pipe 110 via theflexible pipe 130. Hence the refrigerant pipe 120 can supply refrigerantfrom the cold air generation system 40 to the ice-making pipe 110 andreturn refrigerant from the ice-making pipe 110 to the cold airgeneration system 40. Thus, the refrigerant supplied from therefrigerant line 45 to the refrigerant pipe 120 may flow toward theice-making pipe 110 via the flexible pipe 130 and thereby cool theice-making unit 30. Thereafter, refrigerant may flow toward therefrigerant line 45 via the flexible pipe 130 and the refrigerant pipe120.

The flexible pipe 130 may be a refrigerant hose configured tointerconnect the ice-making pipe 110 and the refrigerant pipe 120 in theopening/closing direction of the door 20 in a region around hinged endportions of the refrigerator main body 10 and the door 20. For example,the flexible pipe 130 may be a refrigerant hose made of any suitabletwistable flexible material and may be fastened to the end portions ofthe ice-making pipe 110 and the refrigerant pipe 120, e.g., by bolts.

In particular, the flexible pipe 130 can be manufactured in a four-layerstructure, for example, including an outer rubber layer, a reinforcinglayer, an inner rubber layer and a resin layer (nylon layer). Thus, theflexible pipe 130 may reduce cold air loss and effectively deliverrefrigerant from the refrigerant pipe 120 installed in the refrigeratormain body 10 to the ice-making pipe 110 installed in the door 20, whilewithstanding frequent opening/closing movement of the door 20.

The control valve may be an ON/OFF valve 150 configured to selectivelyopen and close a flow path of the refrigerant in an end portion of therefrigerant pipe to selectively cut off a flow of the refrigerantflowing between the ice-making pipe 110 and the refrigerant pipe 120. Asillustrated in FIG. 3, the opening/closing valve 150 may be installed ineach of an end portion of the refrigerant pipe 120 and an end portion ofthe ice-making pipe 110.

Thus, when the door 20 needs to be removed for repair or replacement,the opening/closing valve 150 can be shut off to stop the flow of therefrigerant prior to removal of the door 20 and thereby to preventleakage of the refrigerant from the refrigerant pipe 120 of the directcooling unit 100.

The pipe case 140 is a case configured to protect the end portion of therefrigerant pipe 120. A heat insulation material such as urethane foamor the like may be filled in the pipe case 140. The pipe case 140 canshield a coupling portion between the refrigerant pipe 120 and theflexible pipe 130. Thereby the internal arrangement can be hidden fromview. A case cover (not shown) for opening and closing an internal spacemay be installed in the pipe case 140.

FIG. 6 is a block diagram illustrating the exemplary cold air generationsystem of the refrigerator according to a first embodiment of thepresent disclosure.

The cold air generation system 40 may supply cold air to therefrigeration compartment and the freezer compartment. Cold air isgenerated through heat exchange between the refrigerant and air flowingin a cooling duct (not shown).

The cold air generation system 40 may include an evaporator 41, acompressor 42 configured to transform the refrigerant discharged fromthe evaporator 41 to a gas state with high temperature and highpressure, a condenser 43 configured to transform the gaseous refrigerantto a liquid state having high pressure, an expansion valve 44 configuredto adiabatically expand the liquid refrigerant and to supply theadiabatically expanded liquid refrigerant to the evaporator 41.

A heat exchange process includes compression, condensation, expansionand evaporation of refrigerant. A freezing cycle includes the compressor42, the condenser 43, the expansion valve 44 and the evaporator 41.Thus, air existing in the cooling duct may be cooled and become cold airthrough heat exchange with refrigerant in the evaporator 41. Thecompressor 42, the condenser 43 and the expansion valve 44 may supplyrefrigerant to the direct cooling unit 100.

More specifically, some refrigerant may be used to generate cold airsupplied to the freezer compartment and the refrigeration compartmentwhile circulating through the evaporator 41, the compressor 42, thecondenser 43 and the expansion valve 44 along the refrigerant line 45.Some refrigerant may be diverted to the ice-making pipe 110 through therefrigerant pipe 120 to cool the ice-making unit 30 and then circulatedagain through the evaporator 41, the compressor 42, the condenser 43 andthe expansion valve 44.

Thus, when the door 20 needs to be removed for repair or replacement,the opening/closing valve 150 can be shut off to stop the flow of therefrigerant prior to removal of the door 20 and thereby to preventleakage of the refrigerant from the refrigerant pipe 120 of the directcooling unit 100.

FIG. 7 is a block diagram illustrating an exemplary cold air generationsystem of the refrigerator according to a modification of the firstembodiment of the present disclosure.

As illustrated in FIG. 7, a three-way valve 160 may be provided at thejunction where the refrigerant pipe 120 is branched from the refrigerantline 45. The three-way valve 160 may selectively cut off a flow of therefrigerant diverted to the direct cooling unit 100 and, therefore, mayhave the same effect as the opening/closing valve 150 described above.

Hereinafter, descriptions will be made on the operation of therefrigerator according to the present embodiment configured as describedabove.

First, if part of the refrigerant is diverted from the refrigerant line45 to the refrigerant pipe 120, the refrigerant in the refrigerant pipe120 may flow toward the ice-making pipe 110 through the flexible pipe130. The flexible pipe 130 can be extended and contracted in theopening/closing direction of the door 20. The flexile pipe 130 enablesthe refrigerant to flow between the refrigerant pipe 120 and theice-making pipe 110 without obstruction or restriction, regardless offrequent movement of the door 20.

The refrigerant in the ice-making pipe 110 may directly cool theice-making tray 33 through the contact portion 110 a. Thus watersupplied to the ice-making tray 33 is directly cooled by the contactportion 110 a and consequently can transform to ice rapidly. Ice piecesproduced in the ice-making tray 33 may fall to the ice bucket 34disposed under the ice-making tray 33 and, then, may be supplied to auser through the dispenser of the door 20.

The refrigerant in the ice-making pipe 110, which has exchanged heatwith the ice-making tray 33, may be moved to the refrigerant pipe 120through the flexible pipe 130. The refrigerant moved to the refrigerantpipe 120 may enter the freezing cycle of the refrigerator through therefrigerant line 45.

Thus, when the door 20 needs to be removed for repair or replacement,the opening/closing valve 150 can be shut off to stop the flow of therefrigerant prior to removal of the door 20 and thereby prevent leakageof the refrigerant from the refrigerant pipe 120 of the direct coolingunit 100.

FIG. 8 is a perspective view illustrating an exemplary refrigeratoraccording to a second embodiment of the present disclosure. FIG. 9 is aview illustrating an exemplary arrangement of an ice-making pipe, arefrigerant pipe and a flexible pipe in the refrigerator according tothe second embodiment of the present disclosure.

As illustrated in FIGS. 8 and 9, in the refrigerator according to asecond embodiment of the present disclosure, the direct cooling unit 100is configured to supply refrigerant from the cold air generation system40 to the ice-making unit 30 through a twistable flexible pipe 130 andis configured to control a flow of the refrigerant by using a controlvalve.

The configurations of various components other than the direct coolingunit 100, including, the configurations of the refrigerator main body10, the door 20, the ice-making unit 30 and the cold air generationsystem 40 have been described with reference to the first embodiment.

The direct cooling unit 100 may supply the refrigerant of the cold airgeneration system 40 to the ice-making unit 130 via the twistableflexible pipe 130 and may control a flow of the refrigerant with theopening/closing valve 150.

The flexible pipe 130 may be a refrigerant hose made of a suitabletwistable flexible material so that the flexible pipe 130 interconnectsthe ice-making pipe 110 and the refrigerant pipe 120 along the up-downdirection of the door 20 and around a hinge shaft of the refrigeratormain body 10 and the door 20. The flexible pipe 130 may be fastened tothe end portions of the ice-making pipe 110 and the refrigerant pipe 120by bolts.

As described above, according to embodiments of the present disclosure,ice pieces are produced using cold air directly cooled in the coolingduct. It is therefore possible to enhance the efficiency of cooling theice pieces and the efficiency of supplying cold air. Cold air iscirculated through a short-cut route between the cooling duct and theice-making space of the refrigerator door. It is therefore possible toeffectively reduce cold air loss. As a consequence, it is possible toreduce power consumption during the operation of the refrigerator.

Although exemplary embodiments of the present disclosure are describedabove with reference to the accompanying drawings, those skilled in theart will understand that the present disclosure may be implemented invarious ways without changing the necessary features or the spirit ofthe present disclosure.

Therefore, it should be understood that the exemplary embodimentsdescribed above are not limiting, but only exemplary in all respects.The scope of the present disclosure is expressed by claims below, notthe detailed description, and it should be construed that all changesand modifications achieved from the meanings and scope of claims andequivalent concepts are included in the scope of the present disclosure.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure. Theexemplary embodiments disclosed in the specification of the presentdisclosure do not limit the present disclosure. The scope of the presentdisclosure will be interpreted by the claims below, and it will beconstrued that all techniques within the scope equivalent thereto belongto the scope of the present disclosure.

What is claimed is:
 1. A refrigerator comprising: a main body defining an outer body of the refrigerator; a door configured to cover an internal space of the main body; an ice-making unit installed in the door; a cold air generation system configured to circulate a refrigerant to generate cold air for supply to the internal space; an ice-making pipe coupled to the cold air generation system and installed in the ice-making unit, wherein the ice-making pipe is configured to supply the refrigerant to the ice-making unit; a refrigerant pipe installed in the main body and operable to receive the refrigerant from the cold air generation system; a flexible pipe configured to interconnect the ice-making pipe and the refrigerant pipe in an extendable manner; and a control valve configured to enable and disable a flow of the refrigerant between the ice-making pipe and the refrigerant pipe.
 2. The refrigerator of claim 1, wherein the flexible pipe is disposed in hinged end portions of the main body and the door.
 3. The refrigerator of claim 1, wherein the flexible pipe is disposed around a hinge shaft that is coupled between the main body and the door.
 4. The refrigerator of claim 1, wherein the control valve comprises an opening/closing valve installed in at least one of an end portion of the refrigerant pipe and an end portion of the ice-making pipe.
 5. The refrigerator of claim 1, wherein the cold air generation system comprises; an evaporator; a compressor; a condenser; and an expansion valve.
 6. The refrigerator of claim 1, wherein the ice-making unit comprises: an ice-making compartment providing space for making ice; an ice-making tray configured to receive water used for transforming into ice pieces, wherein the ice-making tray directly contacts the ice-making pipe; and an ice bucket positioned under the ice-making tray for storing ice pieces supplied from the ice-making tray.
 7. The refrigerator of claim 6, wherein the ice-making unit further comprises a heater disposed in a peripheral edge portion of the ice-making tray.
 8. The refrigerator of claim 1 further comprising a pipe case configured to surround an end portion of the refrigerant pipe.
 9. A refrigerator comprising: a main body defining an outer body of the refrigerator; a door configured to cover an internal space of the main body; an ice-making unit mounted in the door; a cold air generation system configured to circulate a refrigerant and to generate cold air for supply to the internal space; and a direct cooling unit configured to selectively supply the refrigerant from the cold air generation system to the ice-making unit through a control valve.
 10. The refrigerator of claim 9, wherein the ice-making unit comprises: an ice-making compartment providing a space for making ice; an ice-making tray configured to receive water used for transforming into ice pieces, wherein the ice-making tray directly contacts an ice-making pipe; and an ice bucket positioned under the ice-making tray for storing ice pieces supplied from the ice-making tray.
 11. The refrigerator of claim 9, wherein the direct cooling unit comprises: the ice-making pipe installed in the ice-making unit and configured to provide a flow path of the refrigerant; a refrigerant pipe installed in the main body and configured to supply the refrigerant from the cold air generation system to the ice-making pipe; and a control valve configured to selectively cut off flow of the refrigerant between the ice-making pipe and the refrigerant pipe.
 12. The refrigerator of claim 11 further comprising a flexible pipe configured to interconnect the ice-making pipe and the refrigerant pipe in a stretchable or twistable manner.
 13. The refrigerator of claim 10, wherein the ice-making unit further comprises a heater disposed in a peripheral edge portion of the ice-making tray.
 14. The refrigerator of claim 11 further comprising a pipe case configured to surround an end portion of the refrigerant pipe.
 15. The refrigerator of claim 12, wherein the flexible pipe is disposed around a hinge shaft that is coupled between the main body and the door.
 16. The refrigerator of claim 11, wherein the control valve comprises an opening/closing valve installed in at least one of an end portion of the refrigerant pipe and an end portion of the ice-making pipe.
 17. The refrigerator of claim 9, wherein the cold air generation system comprises: an evaporator; a compressor; a condenser; and an expansion valve. 